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Risks of non-conservative design according to ASME B31.1 for high-temperature piping subjected to long-term operation in the creep range

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Nuclear Science and Techniques 2019年第5期30卷 59-69页

作者： Hyeong-Yeon Lee Seok-Kwon Son Min-Gu Won Ji-Young Jeong Korea Atomic energy research institute National fusion research institute School of Mechanical Engineering Sungkyunkwan University

This study investigates the risks of non-conservative piping design according to ASME B31.1 for hightemperature piping subjected to long-term operation at high temperature in a creep regime based on a sensitivity analysis of the hold time. Design evaluations of hightemperature piping were conducted over a range of hold times in the creep regime according to ASME B31.1,which implicitly considers the creep effects, and the French high-temperature design code of the RCC-MRx, which explicitly considers the creep effects. Conservatisms were quantified among the codes in terms of the hold times. In the case of B31.1, the design evaluation results do not change depending on the hold time at high temperature,whereas in the case of RCC-MRx, they do. It was shown that the design limits of RCC-MRx were exceeded when the hold time exceeded certain values, whereas those of B31.1 were satisfied regardless of the hold times. Thus, the design evaluations according to B31.1 did not consistently yield conservative results and might lead to non-conservative results in the case of long-term operations in the creep range.

关键词： ASME B31.1 Creep Hold time Hightemperature piping RCC-MRx Sensitivity analysis

Observation of Impurity Accumulation After Hydrogen Multi-Pellet Injection in Large Helical Device

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Plasma Science and Technology 2013年第3期15卷 230-234页

作者：董春凤 Shigeru MORITA Motoshi GOTO 王二辉 Gen MOTOJIAMA Izumi MURAKAMI Ryuichi SAKAMOTO Norimasa YAMAMOTO National institute for fusion Science Department of fusion Science Graduate University for Advanced Studies Center of Applied Superconductivity & Sustainable energy research Chubu University

Impurity accumulation is studied for neutral beam-heated discharges after hydrogen multi-pellet injection in Large Helical Device （LHD）. Iron density profiles are derived from radial profiles of EUV line emissions of FeXV-XXIV with the help of the collisional-radiative model. A peaked density profile of Fe2a＋ is simulated by using one-dimensional impurity transport code. The result indicates a large inward velocity of -6 m/s at the impurity accumulation phase. However, the discharge is not entirely affected by the impurity accumulation, since the concentration of iron impurity, estimated to be 3.3x10-5 to the electron density, is considerably small. On the other hand, a flat profile is observed for the carbon density of C6＋, which is derived from the Zeff profile, indicating a small inward velocity of -1 m/s. These results suggest atomic number dependence in the impurity accumulation of LHD, which is similar to the tokamak result.

关键词： impurity accumulation EUV spectrometer inward velocity

Measurement of integral diffraction coefficients of crystals on beamline 4B7 of Beijing Synchrotron Radiation Facility

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Chinese Physics B 2011年第1期20卷 276-283页

作者：杨家敏甘新式赵阳崔明启朱托赵屹东孙丽绢郑雷鄢芬胡智民韦敏习张继彦易荣清 research Center of Laser fusion Chinese Academy of Engineering Physics institute of High energy Physics Chinese Academy of Sciences

Integral diffraction coefficients of the crystal are the essential data of a crystal spectrometer which is extensively used to measure quantitative x-ray spectra of high temperature plasmas in kilo-electron-volt region. An experimental method has been developed to measure the integral diffraction coefficients of crystals on beamline 4B7 of Beijing Synchrotron Radiation Facility. The integral diffraction coefficients of several crystals including polyethylene terephthalate （PET）, thallium acid phthalate （T1AP） and rubidium acid phthalate （RAP） crystals have been measured in the x-ray energy range 2100-5600 eV and compared with the calculations of the ＇Darwin Prins＇ and the ＇Mosaic＇ models. It is shown that the integral diffraction coefficients of these crystals are between the calculations of the ＇Darwin Prins＇ and the ＇Mosaic＇ models, but more close to the ＇Darwin Prins＇ model calculations.

关键词： integral diffraction coefficient crystal x-ray spectrum measurement high temperature plasmas

Runaway Electron Suppression by ECRH and RMP in KSTAR

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Plasma Science and Technology 2013年第2期15卷 119-122页

作者： A. C. ENGLAND Z. Y. CHEN D. C. SEO J. CHUNG Y. S. LEEV J. W. YOO W. C. KIM Y. S. BAE Y. M. JEONV J. G. KWAK M. KWON KSTAR Team National fusion research institute Daejeon Republic of Korea Huazhong University of Science and Technology National fusion research institute Daejeon Republic of Korea

We have observed reduction of the runaway electron synchrotron radiation, hard X-ray （HXR） intensity, and HXR energy after applying 110 GHz 2nd harmonic electron cyclotron resonant heating （ECRH） during runaway electron （RE） discharges at low density with startup runaway electrons. However, we did not see a significant reduction of X-rays from 170 GHz 2nd harmonic ECRH at a higher field. A recently installed IR TV camera was used to observe the forward cone of synchrotron radiation from high energy REs in KSTAR. We have observed changes to the synchrotron images and reduction of the HXR by application of resonant magnetic perturbations （RMP） from in-vessel control coils （IVCC） installed inside KSTAR in the n----1 configuration.

关键词： tokamak runaway electron suppression X-ray synchrotron radiation

Quantitative Measurement of the Proportions of High-Order Harmonics for the 4B7B Soft-X-Ray Source at Beijing Synchrotron Radiation Facility

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Plasma Science and Technology 2013年第12期15卷 1194-1196页

作者：朱托尚万里张文海杨家敏熊刚赵阳况龙钰赵屹东郑雷崔明启唐坤马陈燕 research Center of Laser fusion China Academy of Engineering Physics institute of High energy Physics Chinese Academy of Sciences

A transmission grating coupled with an X-ray charge coupled device （CCD） is used to quantitatively measure the proportion of high-order harmonics of the soft-X-ray source of beam line 4B7B. The results show that the monochromatic X-ray has third-order and second-order harmonics. The proportion of second-order harmonic of 4B7B is less than 9.0% and the third- order harmonic is below 0.7% when no suppressing method is applied. When suppression methods are used, the proportion of second-order harmonic is less than 1.7% and the third-order harmonic is ignorable.

关键词： quantitative measurement high-order harmonics suppressing method

Overall Features of EAST Operation Space by Using Simple Core-SOL-Divertor Model

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Plasma Science and Technology 2006年第1期8卷 114-117页

作者： R.HIWATARI A.HATAYAMA 朱思铮 T.TAKIZUKA Y.TOMITA Oentral research institute of Electric Power Industry TokyoJapan Faculty of Science and Technology Keio UniversityYokohamaJapan institute of Plasma Physics Chinese Academy of SciencesHefei230031 China Naka fusion energy Establishment Japan Atomic Energy Research InstituteIbarakiJapan National institute for fusion Science TokiJapan

A simple Core-SOL-Divertor （C-S-D） model has been developed to investigate qualitatively the overall features of the operational space for the integrated core and edge plasma. To construct the simple C-S-D model, a simple core plasma model of ITER physics guidelines and a two-point SOL-divertor model are used. The simple C-S-D model is applied to the study of the EAST operational space with lower hybrid current drive experiments under various kinds of trade-off for the basic plasma parameters. Effective methods for extending the operational space are also presented, From this study for the EAST operational space, it is evident that the C-S-D model is a useful tool for understanding qualitatively the overall features of the plasma operational space.

关键词： divertor modeling particle balance core-edge interface EAST

Development of the PARASOL Code and Full Particle Simulation of Tokamak Plasma with an Open-Field SOL-Divertor Region Using PARASOL

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Plasma Science and Technology 2011年第3期13卷 316-325页

作者： T. TAKIZUKA Japan Atomic energy Agency Naka Fusion Institute Naka 311-0193 Japan

The PARASOL code and the simulation by using PARASOL are introduced briefly. The PARASOL code with particle-in-cell （PIC） method and binary collision model was developed in JAERI and JAEA. Simulations using PARASOL code were carried out in order to investigate the power and particle control with diveror system in fusion reactors. The one-dimensional （1D） version of PARASOL was adopted to investigate the Bohm criterion, the supersonic flow, the SOL heat conduction, and so on. The heat propagation due to edge localized mode （ELM） was studied with the 1D-dynamic PARASOL. The two-dimensional version of PARASOL for the whole tokamak plasma including scrape-off-layer （SOL）-divertor region was useful for simulating the SOL flow pattern, the electric field formation etc. Based on PARASOL simulation results, improved physics modeling for the fluid simulation was built up.

关键词： tolkamak plasma scrape-off layer divertor sheath heat transport plasmaflow radial electric field particle simulation collision model

Global and Kinetic MHD Simulation by the Gpic-MHD Code

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Plasma Science and Technology 2011年第5期13卷 528-534页

作者： Hiroshi NAITOU Yusuke YAMADA Kenji KAJIWARA Wei-li LEE Shinji TOKUDA Masatoshi YAGI Graduate School of Science and Engineering Yamaguchi University Princeton Plasma Physics Laboratory International fusion energy research Center research institute for Applied Mechanics Kyushu University Japan Atomic energy Agency

In order to implement large-scale and high-beta tokamak simulation, a new algorithm of the electromagnetic gyrokinetic PIC （particle-in-cell） code was proposed and installed on the Gpic-MHD code [Gyrokinetic PIC code for magnetohydrodynamic （MHD） simulation]. In the new algorithm, the vorticity equation and the generalized Ohm＇s law along the magnetic field are derived from the basic equations of the gyrokinetic Vlasov, Poisson, and Ampere system and are used to describe the spatio-temporal evolution of the field quantities of the electrostatic potential φ and the longitudinal component of the vector potential Az. The basic algorithm is equivalent to solving the reduced-MHD-type equations with kinetic corrections, in which MHD physics related to Alfven modes are well described. The estimation of perturbed electron pressure from particle dynamics is dominant, while the effects of other moments are negligible. Another advantage of the algorithm is that the longitudinal induced electric field, ETz = -δAz/δt, is explicitly estimated by the generalized Ohm＇s law and used in the equations of motion. Furthermore, the particle velocities along the magnetic field are used （vz-formulation） instead of generalized momentums （pz-formulation）, hence there is no problem of ＇cancellation＇, which would otherwise appear when Az is estimated from the Ampere＇s law in the pz-formulation. The successful simulation of the collisionless internal kink mode by the new Gpic-MHD with realistic values of the large-scale and high-beta tokamaks revealed the usefulness of the new algorithm.

关键词： tokamak gyrokinetic theory magnetohydrodynamics internal kink mode

Bayesian edge detector for SAR imagery using discontinuity-adaptive Markov random feld modeling

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Chinese Journal of Aeronautics 2013年第6期26卷 1534-1543页

作者： Yuan Zhan He You Cai Fuqing research institute of Information fusion Technology Naval Aeronautical and Astronautical University

Synthetic aperture radar（SAR）image is severely affected by multiplicative speckle noise,which greatly complicates the edge *** this paper,by incorporating the discontinuityadaptive Markov random feld（DAMRF）and maximum a posteriori（MAP）estimation criterion into edge detection,a Bayesian edge detector for SAR imagery is accordingly *** the proposed detector,the DAMRF is used as the a priori distribution of the local mean reflectivity,and a maximum a posteriori estimation of it is thus obtained by maximizing the posteriori energy using gradient-descent *** normalized ratios constructed in different directions are computed,based on which two edge strength maps（ESMs）are *** fnal edge detection result is achieved by fusing the results of two thresholded *** experimental results with synthetic and real SAR images show that the proposed detector could effciently detect edges in SAR images,and achieve better performance than two popular detectors in terms of Pratt＇s fgure of merit and visual evaluation in most cases.

关键词： Discontinuity-adaptive Markov random feld(DAMRF) Edge detection Local mean reflectivity Maximum a posteriori(MAP) estimation Synthetic aperture radar(SAR